# HTTP 413 Content Too Large (Request Entity Too Large)

**Code:** `413` · **Category:** HTTP · **Seen on:** Nginx, PHP, Node.js, Apache

The request body is bigger than the server is willing to accept — usually a file upload over the configured limit.

## Meaning

Every layer between the client and your code has its own maximum body size: CDN, load balancer, web server and language runtime. A 413 comes from whichever layer has the smallest limit. Nginx’s default `client_max_body_size` is only 1 MB.

## Common causes

- Nginx `client_max_body_size` (default 1m) too small
- PHP `upload_max_filesize` / `post_max_size` limits
- Apache `LimitRequestBody`
- Framework body-parser limits (Express `json({ limit })` default 100kb)
- CDN/load balancer limits (Cloudflare Free: 100 MB, API gateways often 10 MB)

## Quick fix

1. Raise `client_max_body_size` in Nginx and reload
2. Raise `upload_max_filesize` and `post_max_size` in php.ini (post ≥ upload)
3. Raise the framework body-parser limit
4. For very large files, upload directly to object storage with pre-signed URLs

## Detailed fix by platform

### Nginx

1. In `http`, `server` or `location`:

```nginx
client_max_body_size 50M;
```

2. Run `sudo nginx -t && sudo systemctl reload nginx`.

### PHP

1. php.ini (or .user.ini on shared hosting):

```ini
upload_max_filesize = 50M
post_max_size = 55M
memory_limit = 256M
```

2. Restart PHP-FPM. Note: when PHP’s limit is exceeded, `$_POST` and `$_FILES` are silently empty rather than a 413.

### Node.js

1. Express:

```javascript
app.use(express.json({ limit: '10mb' }));
app.use(express.urlencoded({ extended: true, limit: '10mb' }));
```


### Apache

1. Set `LimitRequestBody 52428800` (bytes) in the vhost or .htaccess.

## How to diagnose

1. **Size** — How large is the request body?
2. **Response origin** — Which layer answered — check the Server header and HTML body of the 413
3. **Limits** — CDN → load balancer → web server → runtime → framework

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Source: [WhatIsMyError](https://whatismyerror.com/errors/http/413-content-too-large)